1. Field of the Invention
This invention relates to a device for automatically tightening and loosening clamps. The specific application of the invention is for clamps in a wood gluing machine; however, the structure and concepts of the invention are usable in any apparatus where clamps are to be tightened or loosened. In fact, the invention is not limited to the tightening or loosening of clamps but may be used to automatically open and close any threaded nut.
2. Description of the Prior Art
U.S. Pat. No. 4,489,925, commonly assigned, discloses a device for clamping a number of wood work pieces. That device has a number of clamp carriers or clamp frames. A plurality of clamps are mounted on each clamp frame or carrier. In operation, the wood pieces to be glued are placed within the jaws of the clamps on each clamp carrier and then a new clamp carrier is brought into operation by removing the wood with the glue having dried, and reinserting new glued pieces of wood therein.
The wood gluing art has long recognized the need to automate what, for many years, has been essentially a manual operation. The field involves the cutting and sizing of strips of wood which are then glued along their edges, clamped together, the glue being allowed to set, and the wooden panel thus formed removed for further processing. Examples of various machinery developed to automate the steps in this basic operation are shown in U.S. Pats. Nos. 4,374,165 and 4,062,320 commonly assigned, where equipment to automate the edge gluing of the strips of wood is disclosed.
The present invention represents an extension of the industry trend to automate various of the steps in the process and involves an apparatus which automatically tightens and loosens the clamps on the machine of the type shown in the aforementioned U.S. Pat. No. 4,489,925.